Chapter 27: Male Reproductive System Practice Flashcards

Vocabulary-style practice flashcards covering male reproductive anatomy, physiology, spermatogenesis, and hormonal regulation based on the provided lecture notes.

Primary sex organs

The organs that produce gametes, specifically the testes in males and ovaries in females.

Gonads

The primary sex organs responsible for producing sperm and egg cells.

Sperm cells

The male gametes produced by the testes.

Egg cells

The female gametes produced by the ovaries.

Secondary sex organs

The organs other than the gonads that are necessary for reproduction.

Male secondary sex organs

A system of ducts, glands, and the penis which delivers sperm cells.

Female secondary sex organs

The uterine tubes, uterus, and vagina which receive sperm and harbor the developing fetus.

Secondary sex characteristics

Features that distinguish the sexes and influence mate attraction, developing at puberty.

Universal secondary sex characteristics

Features found in both sexes, including pubic and axillary hair, associated scent glands, and pitch of the voice.

Male secondary sex characteristics

Facial hair, coarse hair on the torso and limbs, and a relatively muscular physique.

Female secondary sex characteristics

Distribution of body fat, breast enlargement, and finer, less conspicuous body hair.

Male external genitalia

The reproductive structures located outside the body cavity, including the scrotum and penis.

Scrotum

A pouch of skin, muscle, and fibrous connective tissue that contains the testes.

Spermatic cord

A bundle of fibrous connective tissue containing the ductus deferens, blood/lymphatic vessels, and the testicular nerve.

Testes

Combined endocrine and exocrine glands that produce sex hormones and sperm.

Ideal sperm production temperature

Approximately $35^\text{o}\text{C}$, which is lower than the core body temperature.

Core body temperature

$37^\text{o}\text{C}$, a temperature at which the testes cannot produce sperm.

Seminiferous tubules

The specific location within the testes where sperm are produced.

Spermatic ducts

A series of channels that sperm travel through after leaving the testis to reach the urethra.

Epididymis

A duct consisting of a head, body, and tail that serves as the site for sperm maturation and storage.

Sperm disintegration

The process where sperm are broken down and reabsorbed by the epididymis if they are not ejaculated.

Ductus deferens

Also known as the vas deferens, it is the tube that enters the pelvic cavity and conveys sperm.

Ampulla

The expanded portion of the ductus deferens before it joins the duct of the seminal vesicle.

Ejaculatory duct

The duct formed by the union of the ductus deferens and the seminal vesicle duct, passing through the prostate.

Vasectomy

A nearly $100\%$ effective form of birth control involving the cutting and ligating of the ductus deferens.

Male urethra

A structure shared by the reproductive and urinary systems that conveys both urine and semen at different times.

Prostatic urethra

The region of the male urethra that is surrounded by the prostate gland.

Intermediate part of the urethra

Also known as the membranous urethra, located in the urogenital diaphragm.

Spongy urethra

The portion of the urethra that runs through the penis and opens at the external urethral orifice.

External urethral orifice

The opening at the end of the spongy urethra where urine and semen exit the body.

Penis

The male copulatory organ.

Penis components

The root and a shaft that ends in the glans penis.

Prepuce

Also called the foreskin, a cuff of loose skin covering the glans penis.

Circumcision

The surgical removal of the prepuce (foreskin).

Internal penis structure

Composed of the spongy urethra and three cylindrical bodies of erectile tissue.

Corpus spongiosum

The erectile body that surrounds the urethra and expands to form the glans penis.

Corpora cavernosa

Paired dorsal erectile bodies found within the penis.

Accessory glands

The three sets of glands: seminal vesicles, prostate, and bulbourethral glands.

Seminal vesicles

Paired glands posterior to the bladder that empty into the ejaculatory duct and produce the majority of semen.

Seminal vesicle fluid

A viscous alkaline secretion that forms $60\%$ of semen volume.

Prostate

A gland surrounding the urethra and ejaculatory duct that contracts during ejaculation.

Prostatic fluid

A milky, slightly acidic fluid that forms $30\%$ of semen volume.

Bulbourethral glands

Glands near the bulb of the penis that produce pre-ejaculate.

Pre-ejaculate

A clear slippery fluid that lubricates the penis and neutralizes residual urine acidity in the urethra.

Benign prostatic hyperplasia

A noncancerous enlargement of the prostate (BPH) that compresses the urethra and obstructs urine flow.

BPH complications

Incomplete bladder emptying, which may promote bladder and kidney infections.

Prostate cancer

The second most common cause of cancer death in U.S. males, affecting $1$ in $6$ men.

Digital exam screening

A physical screening method used to detect prostate cancer.

Semen

A milky-white mixture of sperm and accessory gland secretions.

Ejaculate volume

Typically between $2\text{--}5\text{ ml}$ of semen.

Sperm concentration

Between $20\text{--}150\text{ million}$ sperm per milliliter ($\text{ml}$).

Fructose in semen

A sugar used for ATP production to provide energy for sperm motility.

Semen alkalinity

A property of seminal fluid that neutralizes the acidity of the male urethra and female vagina.

Spermatogenesis

The process of sperm production occurring within the seminiferous tubules.

Puberty onset in males

The time when spermatogenesis begins, typically around age $14$.

Daily sperm production

Adult males create approximately $90\text{ million}$ sperm every day.

Mitosis

Cell division where a diploid ($2n$) parent cell divides into two genetically identical daughter cells.

Meiosis

Cell division where a diploid ($2n$) parent cell produces four haploid ($n$) gametes.

Diploid ($2n$)

A cell containing the full double set of DNA/chromosomes.

Haploid ($n$)

A cell containing only half the DNA of the parent diploid cells, specifically $23$ chromosomes.

Meiosis I

The first cell division in meiosis, involving prophase I, metaphase I, anaphase I, and telophase I.

Prophase I

The stage where pairs of homologous chromosomes line up and crossing-over occurs.

Crossing-over

The process in meiosis that creates new combinations of genes.

Anaphase I

The meiosis stage where homologous chromosomes are separated and pulled to the poles.

Post-Meiosis I status

Each cell is haploid with $23$ chromosomes, and each chromosome is double-stranded.

Meiosis II

The second division of meiosis where chromatids are separated, resulting in four haploid cells.

Anaphase II

The stage of meiosis II where chromatids are separated and pulled to opposite poles.

Post-Meiosis II status

Each haploid daughter cell contains $23$ single-stranded chromosomes.

Spermatogonia

Stem cells that divide by mitosis to initiate the process of spermatogenesis.

Type A spermatogonium

A daughter cell that remains in the tubule to maintain the pool of dividing germ cells.

Type B spermatogonium

A daughter cell that develops into a primary spermatocyte.

Primary spermatocyte

A diploid cell that undergoes meiosis I to produce two haploid secondary spermatocytes.

Secondary spermatocyte

A haploid cell that undergoes meiosis II to produce two haploid spermatids.

Spermatid

A haploid cell; four are produced from each original spermatogonium.

Spermiogenesis

The transformation of a spermatid into a functional sperm, involving the formation of a flagellum and loss of cytoplasm.

Sperm head

The genetic region of the sperm containing the nucleus and the acrosome.

Acrosome

A helmet-like structure on the sperm head containing hydrolytic enzymes used to penetrate the egg.

Sperm midpiece

The metabolic region of the sperm containing mitochondria that produce ATP.

Sperm tail

The locomotor region of the sperm consisting of a flagellum.

Nurse cells

Also called Sertoli cells, these are supporting cells that play a critical role in sperm formation.

Spermatogenic cells

Cells within the seminiferous tubules that give rise to sperm.

Myoid cells

Smooth muscle-like cells that contract to squeeze sperm and fluid through the tubules.

Interstitial endocrine cells

Also called Leydig cells, these cells secrete testosterone.

Blood-testis barrier

A barrier formed by tight junctions between nurse cells that prevents sperm antigens from activating the immune system.

Nurse cell phagocytosis

The process by which nurse cells consume and destroy faulty germ cells.

Androgen-binding protein

A regulator (ABP) produced by nurse cells that keeps testosterone levels high to stimulate spermatogenesis.

Inhibin

A hormone from nurse cells that reduces spermatogenesis by inhibiting FSH release from the anterior pituitary.

HPG axis

The hypothalamo-pituitary-gonadal axis, which regulates reproductive function.

GnRH

Gonadotropin-releasing hormone, produced by the hypothalamus to stimulate the anterior pituitary.

Anterior pituitary gonadotropins

FSH (follicle-stimulating hormone) and LH (luteinizing hormone).

LH function (Male)

Stimulates interstitial endocrine cells to produce testosterone.

FSH function (Male)

Stimulates nurse cells to secrete androgen-binding protein (ABP).

Testosterone negative feedback

The process where rising testosterone reduces GnRH secretion to maintain hormonal balance.

Andropause

The period of declining testosterone secretion and associated changes in aging males.

Effects of reduced testosterone

Reduced libido, loss of muscle mass, loss of bone density, and decline in sperm motility.

Erectile dysfunction

Also called impotence; the inability to produce or sustain an erection sufficient for intercourse.

Male sexual response phases

Excitement, Plateau, Orgasm, and Resolution.

Excitement phase

Characterized by vasocongestion, myotonia, and increases in heart rate and blood pressure.

Vasocongestion

The swelling of genitals with blood during the excitement phase.

Myotonia

Muscle tension that increases during the excitement and plateau phases.